Alternative solvents for lipid extraction and their effect on protein quality in black soldier fly (Hermetia illucens) larvae

Scrutiny of alternative solvents for the extraction of lipid constituents from black soldier fly (BSF) was the main theme of this research. The present investigation compared a wide array of solvents for the extraction of desired components theoretically using tools like Hansen solubility parameters (HSP), conductor-like screening model for real solvents (COSMO-RS) and technical data (ACD labs) with the application of hurdle technology for solvent screening. The ideal solvent selected was 2-methyloxolane (2-MeO) which was employed for conventional and multistage cross-current lipid extraction and the experimental data obtained was compared with that of n-hexane extract. Fatty acid profile, lipid class, bioactivity of the oils were analysed and were in good correlation with the theoretical prediction. The kinetics and diffusion modelling for the extraction system was proposed. The effect of solvent on protein quality parameters like protein dispersibility index, solubility in alkaline solution, urease index in the defatted flour was elucidated. The defatting step had no deleterious effect on the molecular weight distribution of soluble proteins. Overall the study manifested that 2-MeO had better lipid recovery, enhanced bioactivity in the BSF oil, and relatively better protein quality in the defatted flour. (C) 2019 Elsevier Ltd. All rights reserved.